1. Field of the Invention
The present invention relates to a computer system, which operates a part of a memory as a special memory area for CPU command conversion or real-time compilation.
2. Description of the Related Art
In a conventional computer system, a CPU itself does not use a special random access memory (RAM) area, and therefore the memory is not allocated dynamically.
Among recently developed computer systems, to achieve compatibility with an existing chip, there is one using a CPU, which has a memory area only for emulation. However, even in such a computer system, no changing or the like of the memory area from its initial set value has been executed.
With regard to such a conventional computer system, there have been provided no computer systems, which include functions to change the capacity of an emulation only memory area from its initial value, nor any functions have been provided to enable a user to change the capacity of the special memory area.
In addition, the capacity of the emulation only memory area is not changed even when the memory area used by an operating system, an application program, and so on, has enough capacity. Thus, although it is possible to increase the capacity of the memory area used by the operating system, the application program, and so on, by extending memory, a memory area only for CPU command conversion or for real-time compilation can not be increased. Consequently, it is impossible to improve performance of the CPU or the computer system in this case.
The present invention was made with the foregoing problems in mind, and it is an object of the present invention to provide a computer system operated with excellent performance for CPU command conversion or real-time compilation.
In order to achieve the foregoing object, in accordance with a first aspect of the present invention, there is provided a computer system for operating a part of a memory as a special memory area for CPU command conversion or real-time compilation, comprising: a CPU; a memory; a memory controller for controlling the memory; a special memory setting table for setting a plurality of memory capacities to be mounted in the computer system, and a capacity setting value of the special memory area corresponding to each of the plurality of memory capacities; and a special memory area setting unit for reading a capacity setting value of the special memory area corresponding to all the memory capacities mounted in the computer system from the special memory setting table at starting time of the computer system, and then setting a special memory area based on the capacity setting value.
According to the computer system in the first aspect of the present invention, the presence of the special memory setting table and special memory area setting unit enables a special memory area to be set based on a pre-optimized capacity setting value, and the computer system to be operated with optimal performance.
In order to achieve the foregoing object, in accordance with a second aspect of the present invention, there is provided a computer system for operating a part of a memory as a special memory area for CPU command conversion or real-time compilation, comprising: a CPU; a memory; a memory controller for controlling the memory; a calculating formula storage unit for storing a formula for calculating a capacity of the special memory area corresponding to a memory capacity, from the memory capacity mounted in the computer system; and a special memory area setting unit for setting a capacity of the special memory area of the computer system based on the calculating formula stored in the calculating formula storage unit at starting time of the computer system.
According to the computer system in the second aspect of the present invention, the presence of the calculating formula storage unit and the special memory area setting unit eliminates the necessity of setting a pre-optimized capacity setting value, and enables a special memory area to be automatically set based on a capacity setting value obtained by optimization calculation carried out based on a mounted memory capacity, and the computer system to be operated with optimal performance.
In order to achieve the foregoing object, in accordance with a third aspect of the invention, there is provided a computer system for operating a part of a memory as a special memory area for CPU command conversion or real-time compilation, comprising: a CPU; a memory; a memory controller for controlling the memory; and a special memory area setting unit including a software interface for setting a capacity setting value of the special memory area based on an operation executed by an operator.
According to the computer system in the third aspect of the present invention, the presence of the special memory area setting unit enables a special memory area to be set based on an optimal capacity setting value, by the operation at the application program level on the operating system, to which the operator is accustomed, and the computer system to be operated with optimal performance.
In order to achieve the foregoing object, in accordance with a fourth aspect of the invention, there is provided a computer system for operating a part of a memory as a special memory area for CPU command conversion or real-time compilation, comprising: a CPU; a memory; a memory controller for controlling the memory; a memory use state monitoring unit for monitoring a use state of the memory by a user; and a special memory area setting unit for setting a capacity of the special memory area based on a monitoring result of the memory use state by the memory use state monitoring unit.
According to the computer system in the fourth aspect of the present invention, the presence of the memory use state monitoring unit and the special memory area setting unit enables an optimal capacity value of the special memory area to be automatically set dynamically based on a memory use state without any needs for the user to care about the setting of the special memory area, and the computer system to be operated with optimal performance.
In this case, preferably, the computer system further comprises, in addition to a first memory area used in a fixed manner as the special memory area, a second memory area set as the special memory area, or released from the setting, and the special memory area setting unit sets the second memory area as the special memory area, or releases the setting.
Thus, the number of places for setting special memory areas is not limited to one, but any can be set, and an area, setting thereof having been released, can be used as a general purpose memory area.
Preferably, the computer system of the present invention further comprises a register for regulating a range of the second memory area set by the special memory area setting unit, and access inhibiting means for inhibiting access to the second memory area set as the special memory area setting unit for purposes other than CPU command conversion or real-time compilation.
Thus, it is possible to prevent any erroneous operations caused by fraudulent access to the second memory area.
Furthermore, in the computer system of the present invention, preferably, the special memory area setting unit obtains a part of a memory area used by an operating system or an application program, and assigns the obtained part as the special memory area.
Thus, without limiting only to a fixed area as the second memory area, the general purpose memory area can be flexibly used as the second memory area.